fpga

520 Articles

Nyan Keys: Because Your Keyboard Is Painfully Slow

December 10, 2023 by 32 Comments

You probably don’t notice keyboard latency when typing or doing mundane tasks, but if you start gaming, that’s also when you might start complaining. Every millisecond counts in that arena. Think your keyboard is fast? Think again. Because unfortunately, no matter what you’ve got in there, that key matrix is slowing you down. What you need is an FPGA-based keyboard with an overkill MCU. You need Nyan Keys.

[Portland.HODL] set out to make the lowest-latency mechanical keyboard possible that would accept any Cherry-compatible switches, and boy howdy, is this thing fast.

Coupled with the STM32F723VET6 MCU is USB 2.0 HS, which has an 8000Hz polling rate. At worst, key latency measures 30μS, which blows the 1mS average out of the water.

Because it uses a Lattice Semi iCE40HX 4k FPGA, each key switch can connect to its own I/O pin, which also eliminates the need for diodes.

It also means that each key switch can have its own “core” — an 8-bit timer that is always counting up to 255. The key can only change its state when the timer reads 255. This acts as a rather clever debounce mechanism.

If all that’s not enough, [Portland.HODL] built an operating system called NyanOS written in C to avoid any performance-reducing overhead. Oh, and it has an opt-in Bitcoin miner.

We’ve seen a lot of keyboards, the fast ones are fast because of the input side — they are chording keyboards that take combinations to type, rather than using one key (or so) per character. The Characorder is so fast that it was banned from competition.

BeagleV Catches Fire With The BeagleV-Fire

November 4, 2023 by 34 Comments

A new BeagleBoard is on the way, full of FPGA hotness: the BeagleV-Fire has been announced. The new $150 Single-Board Computer (SBC) from the pioneering open source BeagleBoard company is built around a RISC-V chip that has FPGA features built in. The BeagleV-Fire is built around the snappily named Microchip PolarFire MPFS025T FCVG484E, a System on a Chip (SoC) that has five Reduced Instruction Set Coding Version 5 (RISC-V) cores and a big chunk of FPGA fabric built in. That means it combines the speed of RISC-V processors with the flexibility of Field Programmable Gate Arrays (FPGA), a big pile of logic gates that can be reprogrammed.

The new BeagleV-Fire includes a sizeable chunk of FPGA to work with: the core chip includes 23 K logic elements and 68 Math blocks, plus 4 Serializer/Deserializer (SerDer) lanes that can throw about 12.7 Gbps of data into and out of the fabric. On the BeagleV-Fire, the main chip is supported by 16 GB of eMMC and 2 GB of LPDDR4 RAM, plus a micro SD slot for extra storage. Gigabit Ethernet is also included, plus USB-C power and a few serial connections for debugging. There is no WiFi built in, but there is an M.2 Key E connection were you could plug in an a wireless adapter if you need it.

Like most other BeagleBoards, the BeagleV-Fire has two headers with 92 pins, which offer access to pretty much every signal on the board, plus lots of analog to digital stuff that works with add-on boards (BeagleBoard refers to them as capes). Also present is the usual 22-pin CSI connector for attaching cameras and other devices.

Want one? They are available for immediate order on BeagleBoard.org or from the usual suspects. It looks like they are already in stock for next-day delivery. If this all sounds familiar, it’s probably because we’ve been posting about this particular board for awhile now, covering both the announcement and first tests. Continue reading “BeagleV Catches Fire With The BeagleV-Fire” →

FPGA Runs IBM 5151 MDA Display

September 13, 2023 by 11 Comments

When it comes to driving a display, you can do all kinds of fancy tricks with microcontrollers to get an image up. Really, though, FPGAs are the weapon of choice for playing with these kinds of signals. [Ted Fried] put one to great work driving an ancient IBM 5151 MDA display, and shared his results on Hackaday.io.

The build relies on a Digilent Arty Z7-20 SOC FPGA development board, which has a beefy 600 MHz ARM processor on board. It also packs 500 MB of DRAM—more than enough for storing pixel data for an ancient display.

To drive the old display, [Ted] whipped up a state machine on the FPGA. It’s tasked with fetching display data from RAM and creating the appropriate timings for the MDA display interface. The images are stored directly in an array in C code running on the ARM core. From there, they are copied into the FPGA’s RAM for trucking out to the display. The 720×350 images are stored as 1 bit per pixel, and are created by converting the original JPEGs into single-bit bitmaps in GIMP, before final conversion into a C code array via utility of [Ted’s] own design.

If you’ve ever wanted to display your images in resplendent amber or green, then this could be the project for you. It’s also just a great way to learn about using FPGAs and interfacing with alternative display technologies. If you’ve been whipping up your own retro display hacks, don’t hesitate to drop us a line.

A Cycle-Accurate Sega Genesis With FPGA

August 4, 2023 by 17 Comments

The Field-Programmable Gate Array (FPGA) is a powerful tool that is becoming more common across all kinds of different projects. They are effectively programmable hardware devices, capable of creating specific digital circuits and custom logic for a wide range of applications and can be much more versatile and powerful than a generic microcontroller. While they’re often used for rapid prototyping, they can also recreate specific integrated circuits, and are especially useful for retrocomputing. [nukeykt] has been developing a Sega Genesis clone using them, with some impressive results.

The Sega Genesis (or Mega Drive) was based around the fairly common Motorola 68000 processor, but this wasn’t the only processor in the console. There were a number of coprocessors including a Z80 and several chips from Yamaha to process audio. This project reproduces a number of these chips which are cycle-accurate using Verilog. The chips were recreated using images of de-capped original hardware, and although it doesn’t cover every chip from every version of the Genesis yet, it does have a version of the 68000, a Z80, and the combined Yamaha processor working and capable of playing plenty of games.

The project is still ongoing and eventually hopes to recreate the rest of the chipset using FPGAs. There’s also ongoing testing of the currently working chips, as some of them do still have a few bugs to work out. If you prefer to take a more purist approach to recreating 90s consoles, though, we recently featured a project which reproduced a Genesis development kit using original hardware.

Thanks to [Anonymous] for the tip!

The Another World Chip

July 14, 2023 by 6 Comments

We cover many recreations of classic computer games on these pages, sometimes on original hardware, other times through ports to newer hardware, or even on emulators. But [Sylefeb]’s version of the Amiga classic Another World is in a class of its own. It doesn’t recreate an Amiga or run an emulator, instead it implements the game itself on a relatively modest Lattice UP5K FPGA.

This feat is possible because of the game’s architecture, it runs on a quite minimalist virtual machine that only needs blitter and rasterising hardware. This makes it a good candidate for the FPGA treatment. [Sylefeb] goes into a deep discussion of the hardware implemented in the FPGA, which makes a solid primer for how some of the 16-bit era games worked. In particular, we needed to read over the section about the rasterisation of polygons more than once. But it’s worth it.

The game can be run on a few dev boards featuring this FPGA, among which we’re particularly pleased to see the MCH 2023 conference badge. It requires a copy of the original to be owned for the game files, but we suspect if you’re this deep in you’d probably see that as a small price to pay.

3D Audio Imaging With A Phased Array Microphone

July 4, 2023 by 26 Comments

Remember the scene from Blade Runner, where Deckard puts a photograph into a Photo Inspector? The virtual camera can pan and move around the captured scene, pulling out impossible details. It seems that [Ben Wang] discovered how to make that particular trick a reality, but with audio instead of video. The secret sauce isn’t a sophisticated microphone, but a whole bunch of really simple ones. In this case, it’s 192 of them, arranged on long PCBs working as the spokes of a wall-art wheel. Quite the conversation piece.

Continue reading “3D Audio Imaging With A Phased Array Microphone” →

FPGA Plays Tic-Tac-Toe

June 24, 2023 by 18 Comments

As computers get more and more powerful and artificial intelligence algorithms improve, few games remain where the best humans can reliably beat their electronic counterparts. In chess this barrier was passed in 2005 with the last human win against a computer, and recently humans lost to computers at go. Simpler games like tic-tac-toe have been solved for all possible positions for a while now, so even a simple computer will always win or tie the game. But that doesn’t mean that there’s nothing left to learn about these games as [Hayden] demonstrates with this tic-tac-toe game built entirely on an FPGA.

[Hayden] is making this as part of a college course on digital design, so it really starts at first principles for working with FPGAs. It’s programmed in Verilog on a Basys 3 board, which also hosts the switches used as the game’s input and handles the VGA video output as well. The build uses state machines to keep track of the moves played on each of the squares, and another state machine to keep track of whether or not the current game has been won. If so, it highlights the winning moves in red, and stops taking further inputs until it is reset. Some more logic ties everything together along with a customized VGA driver to produce the entire gaming experience.

A game like tic-tac-toe is a great way to master the fundamentals of a system like this before moving on to more complex programs, especially on an FPGA platform that might handle a lot of the things we take for granted on more traditional computing systems, such as the video output. If you’re interested in taking more of a deep dive into the world of FPGAs, we published a primer about them a few years ago that will get you started.

Continue reading “FPGA Plays Tic-Tac-Toe” →